The Space-based Variable Objects Monitor (SVOM) Visible Telescope (VT) is critical for the rapid identification of gamma-ray burst (GRB) optical counterparts, particularly for high-redshift candidates that require immediate infrared spectroscopic follow-up. To address the stringent bandwidth constraints of the Very High Frequency (VHF) downlink while ensuring real-time data availability, we developed the VT Onboard Data Processing Pipeline (VOPP). This paper details the software architecture, algorithms, and hardware implementation of VOPP using a Field-Programmable Gate Array and a CPU. The pipeline performs essential real-time tasks, including image quality assessment, dark and flat-field correction, and optimized image stacking to mitigate cosmic ray contamination and variable background noise. Furthermore, it generates compact source catalogs and highly compressed 1 bit images to facilitate rapid downlink. In-flight performance analysis confirms the pipeline’s robustness, demonstrating the availability of VT VHF data for 78% of promptly slewed SVOM GRBs, with 56% leading to the identification of optical counterparts, typically within 18 minutes post-trigger.